Abstract or Summary

Because of the prevalence of algae in rice paddy fields, they will be exposed to Bacillus thurigiensis (Bt) proteins released from Bt protein-expressing genetically engineered rice. To assess the effects of leachates extracted from Cry1Ca-expressing transgenic rice (T1C-19) straw on the microalga Chlorella pyrenoidosa, we added purified Cry1Ca (10, 100, 1000 µg/L) and five concentrations of diluted extracts (5, 10, 20, 40, 80%) from T1C-19 and the non-transformed control strain MH63 into the medium of C. pyrenoidosa. We found that (1) the growth curves ofC. pyrenoidosa treated with purified Cry1Ca were overlapping with the medium control; (2) the order of C. pyrenoidosa growth rates for the T1C-19 leachate concentrations was 5% > 10% > 20% > control > 40% > 80% and for the MH63 concentrations was 5% > 10% > control > 20% > 40% > 80%, but there were no statistical differences between the 20% T1C-19 or 20% MH63 leachate treatment and the medium control on day 8; (3) after 7 days of culture, Cry1Ca could be detected in C. pyrenoidosa treated with different concentrations of T1C-19 leachate. Our results demonstrated that Cry1Ca protein released from T1C-19 rice can be absorbed into C. pyrenoidosa, but that purified Cry1Ca and leachates from T1C-19 rice have no obvious adverse effects on the growth of C. pyrenoidosa.